The invention relates to a display device having a cathode ray tube comprising an in-line electron gun for generating three in-line electron beams in a neck of the cathode ray tube, the in-line electron gun comprising a main lens part having three apertures for passing the three electron beams, and a deflection unit, the display device having means to supply an anode voltage to an electrode of the main lens and having a cathodoluminescent phosphor screen provided on a viewing panel of the cathode ray tube.
Display devices of the type mentioned in the first paragraph are used, for instance, in computer monitors and television apparatuses.
Display devices of the type mentioned in the first paragraph are known and on the market.
In operation, such display devices consume power. The operating power adds to the total cost of an apparatus, but apart from the cost factor, the power consumption of in particular computer monitors is an issue of environmental concern. This has led, e.g., to the EPA "Energy Star" guidelines, which most likely will be gradually included in legislation as well. From June 1998 a new IEC standard 1000-3-2 will become effective which sets standard limits for harmonic currents injected into the public supply system for all applications having an active input power exceeding 75 Watt. Depending on the size, computer monitors have averagely an active input power of around 80-85 Watt. Therefore, it is important, from the point of view of environmental concern, to reduce the power consumption of such display devices.